offline_items_collection : Added helper class to determine progress

chrome/android/java/strings/android_chrome_strings.grd

 <?xml version="1.0" encoding="UTF-8"?>
 
 <!-- android_chrome_strings.grd contains strings for Chrome for Android.
 
 FAQ:
   - How do I add, change, or remove a string?
       Just update this file.
   - Translations will happen automatically??
       Yes, indeed. Just add your string before the branch point and
       make the description good.
@@ skipping 1908 matching lines @@
       </message>
       <message name="IDS_DOWNLOAD_SUCCEEDED_MESSAGE_DEFAULT" desc="Transient message shown when a file download has succeeded." meaning="Android">
         <ph name="FILE_NAME">%1$s<ex>http://abc.com/test.pdf</ex></ph> downloaded
       </message>
       <message name="IDS_FILE_SIZE_DOWNLOADED_KB" desc="Notification message showing how many KBs have been downloaded.">
         Downloaded <ph name="KBS">%1$.1f<ex>10.1</ex></ph> KB
       </message>
       <message name="IDS_FILE_SIZE_DOWNLOADED_MB" desc="Notification message showing how many MBs have been downloaded.">
         Downloaded <ph name="MBS">%1$.1f<ex>10.1</ex></ph> MB
       </message>
+      <message name="IDS_ONE_FILE_LEFT" desc="Message showing 1 file left">
+        1 file left
+      </message>
+      <message name="IDS_FILES_LEFT" desc="Message showing how many files are left.">
+        <ph name="FILES">%1$d<ex>10</ex></ph> files left
+      </message>
       <message name="IDS_FILE_SIZE_DOWNLOADED_GB" desc="Notification message showing how many GBs have been downloaded.">
         Downloaded <ph name="GBS">%1$.1f<ex>10.1</ex></ph> GB
       </message>
       <message name="IDS_REMAINING_DURATION_DAYS" desc="Message to show remaining duration in multiple days">
         <ph name="DAYS">%1$d<ex>2</ex></ph> days left
       </message>
       <message name="IDS_REMAINING_DURATION_ONE_DAY" desc="Message to show remaining duration in 1 day">
         1 day left
       </message>
       <message name="IDS_REMAINING_DURATION_HOURS" desc="Message to show remaining duration in multiple hours">
@@ skipping 1038 matching lines @@
         Remove and recreate this shortcut
       </message>
 
       <!-- Chrome Home -->
       <message name="IDS_BOTTOM_SHEET_HELP_BUBBLE_MESSAGE" desc="Text displayed in a help bubble above the bottom navigation sheet prompting users to pull the sheet up to see their bookmarks and other content.">
         Pull up to see bookmarks and more
       </message>
     </messages>
   </release>
 </grit>